local gui = require "navigator.gui"
local diagnostic_list = {}

_NG_VT_NS = vim.api.nvim_create_namespace("navigator_lua")
local util = require "navigator.util"
local log = util.log
local trace = require"guihua.log".trace
-- trace = log
local error = util.error

local path_sep = require"navigator.util".path_sep()
local path_cur = require"navigator.util".path_cur()
diagnostic_list[vim.bo.filetype] = {}

local function error_marker(result, client_id)
  if _NgConfigValues.lsp.diagnostic_scrollbar_sign == nil then -- not enabled or already shown
    return
  end
  local first_line = vim.fn.line('w0')
  local ft = vim.fn.expand('%:h:t') -- get the current file extension

  local bufnr = vim.uri_to_bufnr(result.uri)
  if bufnr ~= vim.fn.bufnr() then
    -- log("not same buf", client_id, result.uri, bufnr, vim.fn.bufnr())
    return
  end

  trace(result, bufnr)

  if result == nil or result.diagnostics == nil or #result.diagnostics == 0 then
    local diag_cnt = vim.lsp.diagnostic.get_count(bufnr, [[Error]])
                         + vim.lsp.diagnostic.get_count(bufnr, [[Warning]])
    if diag_cnt == 0 and _NG_VT_NS ~= nil then
      vim.api.nvim_buf_clear_namespace(bufnr, _NG_VT_NS, 0, -1)
    end
    return
  end

  -- total line num of current buffer
  local winid = vim.fn.win_getid(vim.fn.winnr())
  local total_num = vim.fn.getbufinfo(vim.fn.winbufnr(winid))[1].linecount
  -- window size of current buffer
  local wwidth = vim.fn.winwidth(winid)
  local wheight = vim.fn.winheight(winid)
  if total_num <= wheight then
    return
  end
  if _NG_VT_NS == nil then
    _NG_VT_NS = vim.api.nvim_create_namespace("navigator_lua")
  end

  vim.api.nvim_buf_clear_namespace(0, _NG_VT_NS, 0, -1)
  if total_num <= wheight then
    first_line = 0
  end
  local pos = {}
  -- pos of virtual text
  for _, diag in pairs(result.diagnostics) do
    if diag.range and diag.range.start and diag.range.start.line then
      local p = diag.range.start.line
      p = util.round(p * wheight / math.max(wheight, total_num))
      if pos[#pos] and pos[#pos].line == p then
        pos[#pos] = {
          line = p,
          sign = _NgConfigValues.lsp.diagnostic_scrollbar_sign[2],
          severity = diag.severity
        }
      else
        table.insert(pos, {
          line = p,
          sign = _NgConfigValues.lsp.diagnostic_scrollbar_sign[1],
          severity = diag.severity
        })
      end
    end
    trace("pos", pos, diag.range.start)
  end

  for i, s in pairs(pos) do
    local hl = 'ErrorMsg'
    if s.severity > 1 then
      hl = 'WarningMsg'
    end
    local l = s.line + first_line
    if l > total_num then
      l = total_num
    end
    vim.api.nvim_buf_set_extmark(bufnr, _NG_VT_NS, l, -1,
                                 {virt_text = {{s.sign, hl}}, virt_text_pos = 'right_align'})
  end
end

local diag_hdlr = function(err, method, result, client_id, bufnr, config)
  trace(result)
  if err ~= nil then
    log(err, config)
    return
  end
  local cwd = vim.fn.getcwd(0)
  local ft = vim.bo.filetype
  if diagnostic_list[ft] == nil then
    diagnostic_list[vim.bo.filetype] = {}
  end
  -- vim.lsp.diagnostic.clear(vim.fn.bufnr(), client.id, nil, nil)

  vim.lsp.diagnostic.on_publish_diagnostics(err, method, result, client_id, bufnr, config)
  local uri = result.uri

  -- log("diag: ", result, client_id)
  if result and result.diagnostics then
    local item_list = {}
    for _, v in ipairs(result.diagnostics) do
      local item = v
      item.filename = assert(vim.uri_to_fname(uri))
      item.display_filename = item.filename:gsub(cwd .. path_sep, path_cur, 1)
      item.lnum = v.range.start.line + 1
      item.col = v.range.start.character + 1
      item.uri = uri
      local head = _NgConfigValues.icons.diagnostic_head
      if v.severity == 1 then
        head = _NgConfigValues.icons.diagnostic_head_severity_1
      end
      if v.severity == 2 then
        head = _NgConfigValues.icons.diagnostic_head_severity_2
      end
      if v.severity > 2 then
        head = _NgConfigValues.icons.diagnostic_head_severity_3
      end
      local bufnr1 = vim.uri_to_bufnr(uri)
      if not vim.api.nvim_buf_is_loaded(bufnr1) then
        vim.fn.bufload(bufnr1)
      end
      local pos = v.range.start
      local row = pos.line
      local line = (vim.api.nvim_buf_get_lines(bufnr1, row, row + 1, false) or {""})[1]
      if line ~= nil then
        item.text = head .. line .. _NgConfigValues.icons.diagnostic_head_description .. v.message
        table.insert(item_list, item)
      else
        error("diagnostic result empty line", v, row, bufnr1)
      end
    end
    -- local old_items = vim.fn.getqflist()
    diagnostic_list[ft][uri] = item_list

    error_marker(result, client_id)
  else
    vim.api.nvim_buf_clear_namespace(0, _NG_VT_NS, 0, -1)
    _NG_VT_NS = nil
  end

end

local M = {}
local diagnostic_cfg = {
  -- Enable underline, use default values
  underline = true,
  -- Enable virtual text, override spacing to 0
  virtual_text = {spacing = 0, prefix = _NgConfigValues.icons.diagnostic_virtual_text},
  -- Use a function to dynamically turn signs off
  -- and on, using buffer local variables
  signs = true,
  -- Disable a feature
  update_in_insert = _NgConfigValues.lsp.diagnostic_update_in_insert or false
}

if _NgConfigValues.lsp.diagnostic_virtual_text == false then
  diagnostic_cfg.virtual_text = false
end
-- vim.lsp.handlers["textDocument/publishDiagnostics"] =
M.diagnostic_handler = vim.lsp.with(diag_hdlr, diagnostic_cfg)

M.show_diagnostic = function()
  vim.lsp.diagnostic.get_all()

  local bufs = vim.api.nvim_list_bufs()
  for _, buf in ipairs(bufs) do
    local bname = vim.fn.bufname(buf)
    if #bname > 0 and not util.exclude(bname) then
      if vim.api.nvim_buf_is_loaded(buf) then
        vim.lsp.diagnostic.get(buf, nil)
      end
    end
  end
  if diagnostic_list[vim.bo.filetype] ~= nil then
    -- log(diagnostic_list[vim.bo.filetype])
    -- vim.fn.setqflist({}, " ", {title = "LSP", items = diagnostic_list[vim.bo.filetype]})
    local results = diagnostic_list[vim.bo.filetype]
    local display_items = {}
    for _, items in pairs(results) do
      for _, it in pairs(items) do
        table.insert(display_items, it)
      end
    end
    -- log(display_items)
    if #display_items > 0 then
      gui.new_list_view({
        items = display_items,
        api = _NgConfigValues.icons.diagnostic_file .. _NgConfigValues.icons.diagnostic_head
            .. " Diagnostic ",
        enable_preview_edit = true
      })
    end
  end
end

M.set_diag_loclist = function()
  if not vim.tbl_isempty(vim.lsp.buf_get_clients(0)) then
    local err_cnt = vim.lsp.diagnostic.get_count(0, [[Error]])
    if err_cnt > 0 and _NgConfigValues.lsp.disply_diagnostic_qf then
      vim.lsp.diagnostic.set_loclist()
    else
      vim.cmd("lclose")
    end
  end
end

local function clear_diag_VT() -- important for clearing out when no more errors
  vim.api.nvim_buf_clear_namespace(0, _NG_VT_NS, 0, -1)
  _NG_VT_NS = nil
end

-- TODO: callback when scroll
function M.update_err_marker()
  if _NG_VT_NS == nil then
    -- nothing to update
    return
  end
  local bufnr = vim.fn.bufnr()

  local diag_cnt = vim.lsp.diagnostic.get_count(bufnr, [[Error]])
                       + vim.lsp.diagnostic.get_count(bufnr, [[Warning]])
  if diag_cnt == 0 and _NG_VT_NS ~= nil then
    vim.api.nvim_buf_clear_namespace(bufnr, _NG_VT_NS, 0, -1)
    return
  end

  -- redraw
  vim.api.nvim_buf_clear_namespace(0, _NG_VT_NS, 0, -1)
  local errors = vim.lsp.diagnostic.get(bufnr)
  if #errors == 0 then
    return
  end
  local result = {diagnostics = errors, uri = errors[1].uri}
  error_marker(result)
end

-- TODO: update the marker
if _NgConfigValues.diagnostic_scrollbar_sign then
  print("config deprecated, set lsp.diagnostic_scrollbar_sign instead")
end

if _NgConfigValues.lsp.diagnostic_scrollbar_sign then
  vim.cmd [[autocmd WinScrolled * lua require'navigator.diagnostics'.update_err_marker()]]
end

return M